Sign-in error for Gmail: Android users experience black screen
Android smartphone users are currently experiencing sign-in errors for their Gmail accounts.
The error occured on October 24, 2013, with a black screen and a message that indicated that Google's servers were unreachable.
Google has confirmed that some of its servers experienced an outage on its Google server status page. (http://www.google.com/appsstatus)
So far there are no reports as to why this outage occurred.